Printing-plate matrix and method of making same



H. M. BLAETZ.

PRINTING PLATE MATRIX AND METHOD OF MAKING SAME.

APPLICATION FILED NOW 6| I919- RENEWED APR. 26, 1921.

' Patented June '28, 1921.

I I 314412 two 32 @4 m UNITED STATES PATENT OFFICE.-

HARRY in. summer rmmnrmrnre, PENNSYLVANIA, AssIGNon TO 111m CONLEY r011. oomrm, or NEW YORK, N. Y., A conrom'rron or NEW JERSEY.

PRINTING-PLATE MATRIX AND METHOD OF MAKING SAME.

Specification of Letters Patent. Patnt d J 28 1 Application filed. November 6, 1919, Serial No. 336,095. Renewed April 2 6, 1921. Serial No. 464

useful improvements in matrices and method of making the same, and has particular application to matrices adapted for use 1n the production of electrotypes.

Heretofore in the manufacture of matrices for making'printing electrotypes' it has been the practice to use a sheet or blank of pure,

soft leadfor the body of the matrix, inasmuch as the lead, owing to its I inherent characteristicsof ductility and capability of manipulation, will readily take impressions when subjected to pressure agalnst an origlnal printing plate or die. Therefore, the "ordinary operation in maklng a matrix by what is known asthe cold-molding process is to impose a lead sheet upon the printing face of the original type or die and subject the same to pressure in an ordinar press to reproduce the printing face in t e lead sheet. However prior to the molding process, the

lead sheet must be subjected'to certain operations which are both tedious and expensiye, and therefore, from a commercial standpoint there are certain disadvantages incident to the use of the pure lead in the making of electrotype matrices and which disadvantages I 0v rcome by my invention.

For example I might state that the operation of preparing a sheet of lead for the 40 matrix molding urposes has always necess1- tated considerab e preliminary work. Lead, owing to its peculiar nature has a tendency to rapidly oxidize on its surface, andthis *oxidization must be'eliminated before the sheet can be used for molding.

Furthermore owing to the extreme softness of the lead sheet the surface is liable to show imperfections, rough spots or pits and the like, due'to imperfect rolling in the making of such sheet. Consequently it is usual to brush or clean the impression face of the lead sheet with a wire brush, for the urpose of" removing the oxidized particles and the rough spots or pits, and after this has been done the sheet is generally coated with a solution of benzin and bees wax and then polished with fine graphite. These prellmlnary operations of preparing the sheet for molding result in the expenditure of cons1derable time and labor, and as the work must be performed by a skilled workman 1t of course increases the expense of makrng the matrix and electroplate.

With my matrix and the method I pursue 1n the making of same I obviate all of these operationsand conditions in addition to providing a matrix which is far superior to the ordinary lead matrix and which produces a high-grade electroplate. My invention consists in thematrix, and 1n the method of making the same set forth .in and falling within the scope of the appended claims.

' In the drawings I have shown a matrix on an enlarged scale, when thickness is considered, the thickness of the matrix as actually made corresponding to that of the blank shown in. Fig. 1.

In the accompanying drawing:

Figure 1, is a perspective view of a blank such as is used for making my matrix,

Fig. 2, is a view partly in section and partly in elevation illustrating the molding of the matrix against the original printing body between the platens of a press, said press platens being merely conventionally illustrated,

Fig. 3 is a cross-sectional view of the resulting molded matrix,

Fig. 4, is a cross sectional view of the complete matrix and showing applied thereto a separating coating which is employed to permit the ready separation of the electroplate shell from the matrix after the ordinary electroplating process has been com-" pleted.

Referring now to the accompanying drawings in detail, the letter B indicates, as an entirety, the sheet or blank from which the matrix is made. This sheet B is of a composite nature and includes a back or base section 1, which is preferably composed of pure lead, and an impression surface'or face section 2 which is made up of an exceedingly .thin homogeneous film or skin of pure tin rolled upon and intimately united with the lead base or back 1. The thinness of this tin facing 2, in comparison with the lead back or base 1 will be appreciated when I state that in actual practice I have found a resorting to such high pressure as would tend to damageboth the matrix being made and the original-used in making the matrix.

Furthermore as pure .lead 'is ductile and easily worked under low pressure my thin tin facing covering the lead back or base will not appreciably interfere with the manip-' ulation of the lead back under pressure, but on the contrary will flex or bend to respond to the movement of the lead back in, the press, thereby taking accurate detail impressions from the original die or plate. As the timfacing will not oxidize in the manner of lead but will .present a bright, clean, highly polished surface, it is not necessary to preliminarily scratch or brush the tin facing nor to polish the same, as must be done in the case of an all lead sheet, and consequently a great saving is obtained in the manufacture of the matrix. Because of its bright, smooth, polished surface I prefer to emplo tin for the skin or foil-like facin 2 an have therefore herein mentione this metal, but Iwish it to be under- .stood that the facing'may be made of a thin homogeneous skin or foil of any other metal possessing the requisite characteristics which are applicable to tin, that is to say I may emplo an metal which when in the nature of a tfiin oil-like skin will readily respond to pressure so as to make the necessary re- I production and --yet will present asmooth,

uniform, highl olished surface which will not readily ox1d1ze and which will not require preliminary treatment.

In making the matrixv the original die or printing plate shown at D, the printing surface of which is to be reproduced, is placed on the lower platen P of a suitable press, and the matrix sheet B is imposed upon the die or plate B with the face 2 in contact with the latter. The upper platen P of the press may then be closed, and under the ordinary or minimum pressure used in the cold molding process the impression may be made and after completion the matrix will appear as shown in i 3. I

After the matrix has been made and it is, (desired to use the same in the production of Sodium bichromate possesses manifest adthe same time, when the electroplate or shell has been deposited in the usual manner, by placing the coated matrix in the electroplating bath for a sufiicient length of time, such electroplate shell, after the electroplating process, may be readily separated or removed from the matrix. This electroplate shell when separated from the mold will present the appearance of highly polished nickel, free from flaws, pits and other imperfections and blemishes. This result is obtained because of the character of the skin-like face 2 of the matrix, which face, as before stated does not require the treatment with or the addition of such material as will be liable to cause imperfections in the face.

While I have herein shown and described a preferred embodiment of my invention I wish it to be understood that 1 do not limit myself to all the precise details herein set' forth by way'of illustration, as modification and variation may be made without departing from the spirit of the invention or exceeding the scope of the appended claims.

lVhat I claim is: 1. A matrix for making printing plates comprising a backing composed of a relatively thick sheet of ductile easily moldable metal and a matrix face mechanically united with said backing and comprising an exceedingly thin film of a relatively hard nonoxidizing metal.

2. A matrix for making printing plates comprising a backing composed of a rela-] I backing and comprising an exceedingly thin homogeneous film of tin, said rolled tin face having plate reproducing depressions and elevatlons therein.

4. A matrix for making. rinting plates com rising backing compose of a relatively thic sheet of lead, a matrix face section united with said backing and comprising an exceedingly thin film of 9. rolled nonoxidizing metal, and a coating composed of a solution of sodium bichromate covering the matrix face. r

5. matrix for making printing plates com risin a backing composed of a relativ y thic sheet of lead, a matrix face intlmately united with said backing and comprising an exceedingly thin film of rolled tin and a coating of sodium bichromate imposed upon the matrix face.

.6. The herein described method of making a matrix for use in the manufacture of printing plates which comprises imposing an exceedingly thin film of a relatively hard non-oxidizing metal upon a relatively thick sheet of ductile metal, placing the composite.

sheet thus formed with the non-oxidizing metallic face thereof in contact with the plate or die ,to be-reproduced, then subjecting the same to pressure while in such position to reproduce the depressions and elevations of the plate'or die face in the nonoxidizing metallic face, then removing the composite sheet and coating the matrix face of the same with a separating agent.

7 The herein described method of making a matrix for'use in the manufacture of printing plates, which comprises imposing an exceedingly thin skin of tin upon a relatively thick backing sheet of lead, placing said composite sheet thus formed with its tin face in contact with the plate or die to be reproduced, then subjecting the same to pressure while in suchposition toireproduce the depressions and elevations of the plate or die face in the tin face, then removing the composite sheet and coating the tin face of the same with a separating solution of sodium bichromate. v

' 8. The herein described method of maka matrix for use in the manufacture of prlnting plates, which comprises rolling an exceedingly thin film of a,- relatively hard non-oxidizing metal upon a relatively thick sheet of ductile metal, placing the composite sheet thus' formed with the non-oxidizing metallic face thereof in contact with the plateor die to be reproduced, then subjecting the same to pressure while in such position to reproduce the depressions and elevations of the plate or die face in the nonoxidizing metallic face.

9. The herein described method of making a matrix for use in the manufacture of printing plates, which comprises rolling an exceedingly thin section of tin upon a relatively thick backing sheet of lead, placing said composite sheet thus formed with its tin face in contact with the plate or die to be reproduced, then subjecting the same to pressure while in such position to reproduce the depressionsand elevations of the plate or die face in the tin face.

In testimony whereof I have hereunto set my hand.

HARRY M. BLAETZ. 

